JP2000247710A - Production of artificial marble - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for producing an artificial marble by which an appearance resembled to the appearance of a natural marble is provided, and properties such as a mechanical strength and hot water resistance can be improved. SOLUTION: This method for producing an artificial marble comprises mixing a composition obtained by formulating at least a hardening agent with a resin for decorating particles, being solid at normal temperature and becoming liquid at a prescribed melting point, at a temperature higher than the melting point of the resin for the decorating particles, solidifying the melted resin, pulverizing the solidified resin to provide plural kinds of the decorating particles, formulating each of the obtained decorating particles with an unhardened liquid resin to provide a composition and molding and hardening the obtained composition. Each of the fluidities of the decorating particles is made different from each other. The fluidities of the decorating particles are made mutually different, for example, by a method of making difference in the melting points of the resins, a method of adding an additive capable of forming a false crosslinking in the resin, and regulating the amount to be added, or the like.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to artificial marble used for, for example, bathtubs, kitchen counters, etc.
The present invention relates to a method for producing artificial marble capable of displaying an appearance closer to the appearance of natural marble.

[0002]

2. Description of the Related Art Conventionally, artificial marble used for bathtubs, kitchen counters, and the like is manufactured by crushing mica, silica sand, and the like, mixing the resulting mixture into a compound for artificial marble, and curing and molding the mixture. In the case of artificial marble, mica is a natural product (inorganic), so the workability (cutting and polishing), which is an advantage of artificial marble, is reduced, and the inside of mica etc. when exposed to warm water is reduced. However, there is a disadvantage that the physical properties of the artificial marble are reduced, for example, the air contained in the artificial marble expands and the artificial marble itself expands.

[0003] In order to eliminate such inconvenience, a marble pattern (marble tone, flow pattern) is applied to artificial marble.
In addition, a decoration technique called a stone pattern or a granite pattern (stone pattern, grain pattern) is applied. Among these decoration techniques, the decoration technique related to marble pattern is one in which another compound containing pigment is poured at the time of casting, a number of well-known methods are adopted, and as a decoration technique for granite pattern, For example, JP-A-59-31134, JP-A-5-31134
No. 214115 and JP-A-5-237948.

The decorating technique disclosed in Japanese Patent Application Laid-Open No. 31134/1984 discloses a method in which a sheet is formed by curing an unsaturated polyester resin and aluminum hydroxide in advance, and the sheet is pulverized and classified to form a decorative particle. Make it. Then, the decorative grains are mixed into an artificial dental compound and cured and molded. In the decoration technique disclosed in Japanese Patent Application Laid-Open No. 5-214115, a cured resin is crushed into first crushed resin particles, and the first crushed resin particles are mixed with a transparent curable resin liquid and cured. Thereafter, this is crushed to form second crushed resin particles, and a mixture of the second crushed resin particles in a transparent curable resin liquid is cured and molded.

Further, the decorating technique disclosed in Japanese Patent Application Laid-Open No. Hei 5-237948 discloses a method of molding and curing an uncured liquid curable resin colored in different colors into a multilayer, and then crushing the cured product having the multilayer structure. To produce resin particles (decorative grains)
A mixture of the resin particles and a transparent curable resin liquid is cured and molded.

[0006]

However, when artificial marble is manufactured using these decorating techniques, it is difficult to obtain an appearance closer to the appearance of natural marble, especially in the case of a stone-grain tone, and it is difficult to obtain physical properties. There was a problem that a decrease was also observed.

That is, for example, Japanese Patent Application Laid-Open No. 5-214115
By adopting the decorating technology disclosed in Japanese Patent Application Laid-Open No. 5-237948 or Japanese Patent Application Laid-Open No. 5-237948, an appearance relatively close to that of natural marble can be obtained, but decorative solids that have been solidified in advance can be converted into a liquid composition ( (Hereinafter referred to as matrix) and hardening molding, so that the boundary between the decorative grains and the matrix becomes clear, a natural boundary like natural marble cannot be obtained, and an appearance closer to natural marble is obtained. It becomes difficult.

Further, since the decorative particles and the matrix having different phase forms composed of a solid phase and a liquid phase are hardened and formed, the adhesion strength and the like at the boundary (interface) between the decorative particles and the matrix due to the shrinkage upon curing of the matrix. It cannot be obtained sufficiently, and the physical properties of artificial marble, such as a decrease in mechanical strength and a decrease in hot water resistance, are observed.

The present invention has been made in view of such circumstances, and an object of the present invention is to provide an appearance closer to the appearance of natural marble, as well as mechanical strength and hot water resistance. It is an object of the present invention to provide a method for producing artificial marble capable of improving the physical properties of artificial marble. Claim 2 or 3
The object of the invention described in the above is an artificial marble in which the flowability of the decorative particles is appropriately adjusted by the difference in the melting point of the resin for the decorative particles in order to obtain a more natural pattern. It is to provide a manufacturing method. Claim 4 or 5
The object of the invention described in addition to the object of the invention described in claim 1 is to appropriately adjust the fluidity of the decorative particles by adding an additive to the resin for decorative particles, thereby obtaining a more natural pattern. An object of the present invention is to provide a method for producing artificial marble.

[0010]

In order to achieve the above object, the invention according to claim 1 of the present invention comprises mixing at least a curing agent with a resin for decorative particles which is solid at room temperature and becomes liquid at a predetermined melting point. The mixed composition is mixed at a temperature higher than the melting point of the resin for decorative particles, and then hardened and pulverized to produce a plurality of types of decorative particles. The present invention relates to a method for producing artificial marble by curing and molding the composition blended in the above, characterized in that the fluidity of the decorative particles is varied.

[0011] With this configuration, a composition in which a hardening agent or the like is blended with a resin for decorative particles which is solid at room temperature and becomes liquid at a predetermined melting point is mixed at a temperature higher than the melting point of the resin for decorative particles. Therefore, at the time of this mixing, the resin for decorative particles becomes substantially liquid and is favorably mixed with, for example, a filler. Also,
The composition is solidified by, for example, returning the mixed composition to room temperature, and the solidified matter is pulverized to produce decorative grains.

[0012] Then, by curing and molding a composition in which a plurality of kinds of decorative grains thus produced are mixed with an uncured liquid resin, a curing agent is decomposed to produce artificial marble.
Decorative particles are cured from a liquid state by a chemical reaction during curing and molding. At this time, since the fluidity of a plurality of types of decorative particles is different from each other, for example, there is a time difference between the heating and melting timing of each decorative particle. Occurs and the boundary with the matrix, which is the surrounding composition, is not clear and becomes slightly blurred, and an appearance closer to the appearance of natural marble is obtained, and the adhesion strength at the interface between the decorative grain and the matrix is And the physical properties such as mechanical strength and hot water resistance are improved.

[0013] The invention according to claim 2 is characterized in that the melting point of the resin for decorative particles is made different so that the fluidity of the decorative particles is made different. A distinction is made in the melting point of each color of the resin for decorative particles or within the same color. With such a configuration, for example, since a plurality of types of resin for decorative particles having different melting points are used, the time difference (fluidity of the decorative particles) between the heating and melting timings of the respective decorative particles can be adjusted as desired. At this time, the colors of the plurality of types of resin for decorative particles having different melting points can be made different or the same, so that artificial marble having a more natural pattern can be obtained.

[0014] Further, the invention according to claim 4 is characterized in that the resin for decorative particles is added with an additive which causes pseudo-crosslinking.
6. The method according to claim 5, wherein the fluidity of the decorative grains is different.
The described invention is characterized in that the additive amount of the additive is made different for each resin for decorative particles. With such a configuration, the resin for the decorative particles used in the addition of the predetermined additive forms an ionic bond (pseudo-crosslinking) between the molecular chains, so that the time difference between the heating and melting timings of the decorative particles is desirably set. In this case, the amount of the additive can be varied depending on the resin for the decorative granules, and an artificial marble having a more natural pattern can be obtained.

[0015]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a process chart showing an example of a method for producing artificial marble according to the present invention. The production method according to the present invention basically includes a first step of producing a plurality of types of decorative grains, and this decorative step. A second step of producing a molded article of artificial marble using the granules.

First, in the first step, a plurality of kinds (A to N in the figure) of a resin in which a decorative particle resin, a filler, a pigment, a curing agent, and the like and an additive are blended in a predetermined part by weight as required. A composition for decorative particles is prepared (K101), and the composition is mixed in an aqueous solution at a predetermined temperature (or in a constant temperature chamber) (S102).
This is returned to normal temperature and solidified (S103) to produce, for example, a plate-shaped composition. As the resin for decorative particles used in this step K101, an unsaturated polyester resin, a vinyl ester resin, an acrylic resin, or the like is used, and the melting point of the resin for decorative particles is 55 ° C. to 90 ° C. And preferably a resin having a melting point of 70 ° C to 80 ° C.

The filler may have an average particle size of about 5 μm.
Aluminum hydroxide, magnesium hydroxide, calcium carbonate, glass powder, etc. of about m to several hundred μm are used, and as the pigment, coloring such as titanium oxide, carbon black, etc., which produces an appropriate color such as white, gray, brown, black, etc. Toner is used. Further, a peroxide, a peroxyester, or the like is used as a curing agent, and magnesium oxide or the like is used as an additive that is added as needed.

Next, the composition solidified in step K103 is ground using a crusher / hammer mill or the like (K104).
Then, the pulverized particles are classified (K105) as necessary. Thereby, a plurality of types of decorative particles A to N having a particle size of about 10 μm to 10 mm are sequentially produced, and the decorative particles A to N
As described later, the resin is formed so that its fluidity is different by changing the melting point of the resin for decorative particles or by changing the amount of additive. Step K104
If the composition is difficult to pulverize at the time of pulverization, the composition is cooled and pulverized in a cooled state.

When a plurality of types of decorative particles A to N are produced in the first step, the process proceeds to a second step. First, an uncured liquid resin, a filler, the decorative particles A to N, A composition for marble is prepared by blending a predetermined amount of an agent and the like (K106)
Then, the composition is kneaded with a kneader or a stirrer (K107) to prepare a compound. Next, the compound is aged as needed (K108), and then is heat-molded (K109) with a predetermined mold. The uncured liquid resin used in the second step is preferably liquid at normal temperature, for example, an unsaturated polyester resin, an epoxy resin, a phenol resin, a melamine resin, a carbon resin or a mixture of these resins and acrylic syrup, Is used.

As the filler, in addition to the filler shown in the first step, glass fiber, magnesium oxide, zinc stearate and the like are used. As the curing agent, the same curing agent as that used in the first step is used. It is preferable to use
As the mold, a BMC bathtub mold or a mold for a kitchen counter is used.

[0021]

Next, a typical method 2 of the manufacturing method according to the present invention will be described.
One embodiment will be described, but the present invention is not limited to these embodiments. (Example 1) The characteristic of the decorative particles produced in the first step of Example 1 is that the melting point of the resin for decorative particles was changed.
For example, nine types of decorative particle compositions (for decorative particles A to I) shown in Table 1 below are prepared.

[0022]

[Table 1]

Then, each of the compositions is mixed in a hot water bath at, for example, 60 ° C. using a mixer. At this time, the unsaturated polyester resin as the resin for the decorative particles A to I can be mixed with the matrix in a liquid state, and the decomposition start temperature of the curing agent is not lower than the melting point of the resin for the decorative particles A to I. Therefore, in the state of the composition, a chemical reaction (for example, radical polymerization) hardly occurs.

When each composition is sufficiently mixed in a hot water bath at 60 ° C., the temperature is returned to room temperature (30 ° C. or lower) (cooling) to lower the melting point of the unsaturated polyester resin. Each of the mixed compositions is solidified to form an apparent solid, and the respective compositions are prepared. In the case of solidification, for example, by making the pellet size, the pulverization described later can be more easily performed. Then, when the composition is sufficiently mixed, cooled and solidified to produce a composition, the composition is pulverized and classified to produce decorative particles A to I having a particle size of about 10 μm to 10 mm, respectively.

After a plurality of types of decorative grains A to I have been prepared in this way, in the second step, the decorative grains A to I
Is used to produce the composition for artificial marble shown in Table 2 below. In addition, a of Table 2 shows the case where the molding method is press molding, and B shows the case of the molding method by casting.

[0026]

[Table 2]

When the composition for artificial marble is prepared, in the case of press molding, the composition is kneaded with a kneading machine such as a kneader to prepare a BMC (bulk molding compound), which is aged, In the case of a mold, the compound is prepared by kneading with a stirrer or the like. And then,
In the case of press molding, a BMC bathtub mold temperature-controlled to 140 ° C. (product side) / lower mold 125 ° C. (back side of product) is charged and heated. In the case of casting, the aged compound is placed in the upper mold at 90 ° C / lower mold at 70 °.
The mixture is poured into a kitchen counter mold whose temperature has been adjusted to C and heat-molded.

At the time of this heat molding, each of the decorative grains A to I has a different melting point (fluidity) and color.
A difference occurs in the heating and melting timing of the particles, and the decorative particles having a low melting point (for example, the decorative particles D, F, and H) melt relatively quickly, and the decorative particles having a high melting point (for example, the decorative particles E, G, and I). Will delay the start of melting. Due to the difference in the melting start timing, the boundaries between the decorative grains A to I and the surrounding matrix are blurred or flow, and the state is slightly different for each of the decorative grains A to I. In the first embodiment, the case where the colored toner of each of the particles A to I has a plurality of colors has been described, but it is of course possible to use the same colored toner for each of the decorative particles A to I. .

(Example 2) The characteristics of the decorative particles produced in the first step of Example 2 are that, for example, an additive is added at the time of producing the decorative particles, and the amount of the additive added to each decorative particle is The difference is that the apparent hardness (cohesive force) of each decorative grain is changed by making them different, and for example, five types of compositions (for decorative grains a to e) shown in Table 3 below are produced, respectively. I do.

[0030]

[Table 3]

Then, this composition was mixed, solidified, pulverized and classified in the same manner as in Example 1 to give decorative granules a.
To e are prepared. The decorative grains a to e thus produced were aged in a maturation room at 40 ° C. for 48 hours after kneading, and the hardness of the bulk composition was measured by rubber hardness measurement. The results shown in Table 4 were obtained. By crushing this bulk using a crusher / hammer mill or continuous cutter,
Decorative grains a to e each having a particle size of about 10 μm to 10 mm are produced.

[0032]

[Table 4]

When a plurality of types of decorative grains a to e are prepared in this manner, the decorative grains a to e are used in the second step in the same manner as in Example 1 to obtain the composition shown in Table 5 below. Make things.

[0034]

[Table 5]

After the composition is prepared, it is kneaded, aged, and heat-formed to form an artificial marble. At the time of this heat-forming, the addition of the additives added to the decorative grains a to e is also performed. Since the amount is different, the hardness (fluidity) of each of the apparent decorative grains a to e can be changed, and the boundary between each of the decorative grains a to e and the surrounding matrix is blurred or flows, The state also slightly differs for each of the decorative grains a to e. In addition, in this Example 2, by making the addition amount of the additive of each of the decorative grains a to e different,
Although the apparent hardness of each of the decorative grains a to e is changed, the fluidity of each of the decorative grains a to e can be changed by changing the aging condition of each of the decorative grains a to e.

In the artificial marble thus formed, the boundary between each of the decorative grains and the surrounding matrix is blurred, and each of the decorative grains themselves flows like, for example, Comet Halley. Unlike the conventional case, the boundaries of the decorative grains are not clear, and an appearance very close to the appearance of natural marble can be obtained. In addition, since the curing of the decorative particles and the curing of the matrix occur almost simultaneously, the adhesion at the interface between the decorative particles and the matrix is increased, and the mechanical strength and hot water resistance of the artificial marble itself are improved as shown below. Has also been confirmed.

That is, the impact resistance as the mechanical strength is the same as the conventional one (JP-A-5-214115 or JP-A-5-214115).
4.5 kg / cm to 7.5 kg / cm of artificial marble obtained by the decoration technique disclosed in JP-A-237948.
/ Cm (according to Izod impact test).
While whitening starts in 00 hours, whitening starts in 500 hours in a hot water contact test at 90 ° C., and the hot water resistance is greatly improved. Furthermore, the decorative particles manufactured by the above-described manufacturing method can be easily manufactured as compared with the method of manufacturing decorative particles disclosed in, for example, JP-A-5-237948, It has been confirmed that the cost can be reduced.

The types of the decorative grains in the above embodiment are as follows:
The manufacturing process itself and the materials and equipment used in each process are merely examples, and the settings can be appropriately changed according to, for example, various products in which the molded artificial marble is used. The present invention also relates to a decorative particle using a resin which is solid at room temperature and becomes a liquid at a predetermined melting point, and wherein each of the decorative particles is formed by heating the artificial marble composition using the decorative particle. The means for varying the fluidity is not limited to the above-described embodiment, and appropriate means can be adopted. Furthermore, the artificial marble according to the present invention can be used not only for bathtubs and kitchen counters but also for other housing-related equipment and other equipment on which natural marble is installed.

[0039]

As described above in detail, according to the first aspect of the present invention, the flowability of the decorative particles using the resin for decorative particles which is solid at room temperature and becomes liquid at a predetermined melting point is varied. In order to cure-mold a composition in which the decorative particles are blended with a filler, a curing agent, an uncured liquid resin, and the like, a difference in melting timing occurs between the decorative particles at the time of curing and molding. The boundary between the grains and the matrix is blurred or flowing, and the appearance closer to the appearance of natural marble is obtained.In addition, the adhesion at the interface between the decorative grains and the matrix is improved, and the mechanical strength and heat resistance are improved. It is possible to improve the physical properties of artificial marble, for example, by increasing aqueous properties.

According to the second or third aspect of the present invention, in addition to the effects of the first aspect of the present invention, since a plurality of types of resin for decorative grains having different melting points are used, heating of each decorative grain is performed. The time difference of the melting timing (fluidity of the decorative particles) can be adjusted as desired. At that time, the colors of the resin for decorative particles having different melting points can be different or can be set to the same value,
You can obtain artificial marble with a more natural pattern.

According to the fourth or fifth aspect of the present invention, in addition to the effect of the first aspect, the resin for decorative particles used in the addition of a predetermined additive is capable of forming an ionic bond (molecular bond) between molecular chains. (Pseudo-crosslinking), it is possible to adjust the time difference of the heating and melting timing of each decorative grain as desired, and at that time, it is possible to vary the amount of additive for each resin for decorative grain, so that a more natural pattern This produces effects such as the ability to obtain artificial marble.

[Brief description of the drawings]

FIG. 1 is a process chart showing an example of a method for producing artificial marble according to the present invention.

Claims (5)

[Claims] 1. A composition obtained by blending at least a hardening agent with a resin for decorative particles which is solid at room temperature and becomes liquid at a predetermined melting point, is mixed at a temperature higher than the melting point of the resin for decorative particles. A method for producing artificial marble by solidifying below the melting point and pulverizing to produce a plurality of types of decorative particles, and then curing and molding a composition in which each of the decorative particles is mixed with an uncured liquid resin. A method of producing artificial marble, characterized in that the fluidity of the decorative grains is varied. 2. The method for producing artificial marble according to claim 1, wherein the flowability of the decorative particles is varied by making the melting point of the resin for decorative particles different. 3. The method for producing artificial marble according to claim 2, wherein the melting point is different for each color or within the same color of the decorative grain resin. 4. The method for producing artificial marble according to claim 1, wherein the flowability of the decorative particles is made different by adding an additive which causes pseudo-crosslinking of the resin for decorative particles. 5. The method for producing artificial marble according to claim 4, wherein the amount of the additive is varied for each resin for decorative particles.